Sen. Susan Collins, R-Maine, is at the top of the Lugar Bipartisan Index, a listing that grades members of the House and Senate according to how well they work with each other, while Vermont Independent Sen. Bernie Sanders, who mounted a race for the Democratic presidential race in 2016, placed last.

According to The Lugar Center, the index was created to "fill a hole" in the information that is usually made public about congressional members' actions.

Overall, with the exception of one senator, Republicans took the top 10 spots in the rankings:

Sen. Susan Collins, R-Maine, is at the top of the Lugar Bipartisan Index, a listing that grades members of the House and Senate according to how well they work with each other, while Vermont Independent Sen. Bernie Sanders, who mounted a race for the Democratic presidential...